When a medicine is approved by the U.S. Food and Drug Administration (FDA) to treat a specific disease or condition, it’s generally understood that research and experience may guide doctors to other uses of the medicine. This is especially true for advanced-stage cancer treatments, when it might be necessary to try all reasonable options to fight the cancer.

The term “off-label” use means that a medicine is being used in a way that hasn’t been officially approved by the FDA. Doctors usually decide to use a medicine off-label to treat specific cancer situations only when research and clinical experience show good evidence that the medicine is effective in that situation. When done this way, off-label use is considered acceptable and appropriate.

A study found that 19% of chemotherapy medicines given to women 65 and older were used off-label.

The research was presented at the 2012 San Antonio Breast Cancer Symposium.

The researchers reviewed the records of 16,898 women 65 or older who were treated with chemotherapy for a first diagnosis of breast cancer. Medicines that had never been approved to treat breast cancer were given to 8% of the women.

Off-label chemotherapy medicines were more likely to be given to women diagnosed with breast cancer at a more advanced stage. The percentages of off-label chemotherapy use by cancer stage were:

Using medicines that had never been approved for breast cancer was most common for stage 4 cancers (12%), as well as for treatments used after a first treatment had stopped working.

Most of the medicines used off-label were medicines that had been approved to treat breast cancer, but were approved for a different stage of breast cancer or for use at a different time during treatment.

Taxol (chemical name: paclitaxel) was the most common medicine used off-label. Taxol is usually given after surgery to treat cancer after it stops responding to standard chemotherapy regimens. The researchers found the doctors were using Taxol as the first chemotherapy medicine after surgery or were sometimes using it before surgery to shrink the cancer.

Other medicines commonly used off-label were:

Taxotere (chemical name: docetaxel)

Herceptin (chemical name: trastuzumab)

Paraplatin (chemical name: carboplatin)

Navelbine (chemical name: vinorelbine)

In most cases, the off-label use was considered acceptable and appropriate to the situation.

The researchers also found that visits to the emergency room and needing to be hospitalized were more likely within 30 days of the off-label chemotherapy being given for women diagnosed with early-stage or locally advanced breast cancer. Locally advanced breast cancer is cancer that has spread beyond the breast to nearby tissue, such as the chest wall.

Still, because most of the off-label use was considered appropriate, it’s likely that many of the women who were getting off-label chemotherapy medicines had more advanced-stage cancer and were considered sicker than women who didn’t get off-label chemotherapy. And sicker women might be more likely to visit the emergency room.

If you’re being treated for breast cancer and are learning about the medicines in your treatment plan, you may find that one or more of your treatments isn’t approved by the FDA for use in your specific situation. Even though a treatment may be off-label, it’s very likely that your doctor recommended it to you based on sound evidence and experience from that treatment being used in women in situations similar to your own. Still, it’s a good idea to talk to your doctor about any off-label medicines being used in your treatment plan and why an off-label treatment might make sense for you and your unique situation.